1. Field of the Invention
The present invention relates to an image capturing apparatus capable of automatically setting an exposure control value and a control method thereof.
2. Description of the Related Art
Conventionally, regarding the ISO sensitivity (imaging sensitivity) of a camera, a function, which when no appropriate exposure can be obtained under an ISO sensitivity set according to a user's instruction, of automatically changing the ISO sensitivity to obtain the appropriate exposure (referred to as automatic sensitivity change function) has been known. Japanese Patent Application Laid-Open No. 2006-222757 discusses an electronic camera capable of changing a set imaging sensitivity when appropriate exposure is not obtained in exposure calculation. The electronic camera can set a control upper limit sensitivity and a control lower limit sensitivity when changing the imaging sensitivity so as not to exceed a range which the user intends.
However, according to Japanese Patent Application Laid-Open No. 2006-222757, the user can input an instruction about the imaging sensitivity only in a range between the control upper limit sensitivity and the control lower limit sensitivity (in a sensitivity control range). Thus, the imaging sensitivity which can be set according to the user's instruction is limited to a particular range and there may be a case where the user cannot set the imaging sensitivity as he or she intends.
In such a case, the range of the imaging sensitivity can be expanded by changing the control upper limit sensitivity or the control lower limit sensitivity. However, the user needs to give an instruction for changing the control upper limit sensitivity or the control lower limit sensitivity, so that his or her intended imaging sensitivity cannot be set immediately. Such an issue may occur also when a technique discussed in Japanese Patent Application Laid-Open No. 2006-222757 is applied to exposure control values other than the imaging sensitivity, for example, an aperture value and a shutter speed.